• Proceedings of the KGS Conference
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• 2006.06a
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• pp.138-139
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• 2006

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.3
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• pp.202-207
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• 2016

Checkpoint placement is an effective fault tolerance technique against transient faults in which the task is re-executed from the latest checkpoint when a fault is detected. In this paper, we propose a new checkpoint placement strategy separating data saving and fault detection processes that are performed together in conventional checkpoints. Several fault detection processes are performed in one checkpoint interval in order to decrease the latency between the occurrence and detection of faults. We address the placement method of fault detection processes to maximize the probability of successful execution of a task within the given deadline. We develop the Markov chain model for a real-time task having the proposed checkpoints, and derive the optimal fault detection and checkpoint interval.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.1 no.1
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• pp.37-43
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• 2007

Internet is essential to live nowadays, but persons with disabilities are hard to use internet because people who develops and operate web sites don't think and comply the web accessibility standard. In order to solve this problem, Korea governments implement a lot of policies such as. making web accessibility standard, operating web accessibility education program, etc.. The purpose of this paper is examined the web accessibility compliance of major web sites such as portal, news, banking, education in Korea. In order to investigate the web accessibility compliance status of major web sites's in Korea, 15 web sites were chosen. This study was used the 4 major checkpoints that must be the crucial among 14 checkpoints in Internet Web Contents Accessibility Guidelines which was amended by Ministry of the Information and Communication in 2005. The results of this study showed that 15 major web sites in Korea didn't meet the 4 major checkpoints.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.3
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• pp.527-534
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• 2023

Triple modular redundancy (TMR) systems can continue their mission by virtue of their structural redundancy even if one processor is attacked by faults. In this paper, we propose a new fault tolerance strategy by introducing checkpoints into the TMR system in which data saving and fault detection processes are separated while they corporate together in the conventional checkpoints. Faults in one processor are tolerated by synchronizing the state of three processors upon detecting faults. Simultaneous faults occurring to more than one processor are tolerated by re-executing the task from the latest checkpoint. We propose the checkpoint placement and fault detection strategy to maximize the probability of successful execution of a task within the given deadline. We develop the Markov chain model for the TMR system having the proposed checkpoint strategy, and derive the optimal fault detection and checkpoint interval.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.905-910
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• 2016

Breast cancer is one of the major threats to female health, and its incidence is rapidly increasing in many countries. Currently, breast cancer is treated with surgery, followed by chemotherapy or radiation therapy, or both. However, a substantial proportion of breast cancer patients might have a risk for local relapse that leads to recurrence of their disease and/or metastatic breast cancer. Therefore searching for new and potential strategies for breast cancer treatment remains necessary. Immunotherapy is an attractive and promising approach that can exploit the ability of the immune system to identify and destroy tumors and thus prevent recurrence and metastatic lesions. The most promising and attractive approach of immunotherapeutic research in cancer is the blockade of immune checkpoints. In this review, we discuss the potential of certain inhibitors of immune checkpoints, such as antibodies targeting cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed death 1 (PD-1) and lymphocyte activation gene-3 (LAG-3), in breast cancer therapeutics. Immune checkpoint inhibitors may represent future standards of care for breast cancer as monotherapy or combined with standard therapies.

• IMMUNE NETWORK
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• v.14 no.6
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• pp.265-276
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• 2014

The interactions between B7 molecules and CD28-family receptors are crucial in the regulation of adaptive cellular immunity. In cancer, the aberrant expression of co-inhibitory B7 molecules has been attributed to reduced anti-tumor immunity and cancer immune evasion, prompting the development of cancer therapeutics that can restore T cell function. Murine tumor models have provided significant support for the targeting of multiple immune checkpoints involving CTLA-4, PD-1, ICOS, B7-H3 and B7-H4 during tumor growth, and clinical studies investigating the therapeutic effects of CTLA-4 and PD-1 blockade have shown exceptionally promising results in patients with advanced melanoma and other cancers. The expression pattern of co-inhibitory B7 ligands in the tumor microenvironment has also been largely correlated with poor patient prognosis, and recent evidence suggests that the presence of several B7 molecules may predict the responsiveness of immunotherapies that rely on pre-existing tumor-associated immune responses. While monotherapies blocking T cell co-inhibition have beneficial effects in reducing tumor burden, combinatorial immunotherapy targeting multiple immune checkpoints involved in various stages of the anti-tumor response has led to the most substantial impact on tumor reduction. In this review, we will examine the contributions of B7- and CD28-family members in the context of cancer development, and discuss the implications of current human findings in cancer immunotherapy.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.4
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• pp.176-184
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• 2002

We provide a checkpointing framework reflecting both the timeliness and the dependability in order to make checkpointing applicable to dependable real-time systems. The predictability of real-time tasks with checkpointing is guaranteed by the worst case execution time (WCET) based on the allocated number of checkpoints and the permissible number of failures. The permissible number of failures is derived from fault tolerance requirements, thus guaranteeing the dependability of tasks. Using the WCET and the permissible number of failures of tasks, we develop an algorithm that determines the minimum number of checkpoints allocated to each task in order to guarantee the schedulability of a task set. Since the framework is based on the amount of time redundancy caused by checkpointing, it can be extended to other time redundancy techniques.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.1
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• pp.170-175
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• 2022

Reactive failure management techniques are required to mitigate the impact of errors in high performance computing. Checkpoint is the standard recovery technique for coping with errors. An application employing checkpoints periodically saves its state, so that when an error occurs while some task is executing, the application is rolled back to its last checkpointed task and resumes execution from that task onward. In this paper, assuming the time-to-errors are independent each other and generally distributed, we analyze the checkpointing model with instantaneous error detection. The conventional assumption that two or more errors do not take place between two consecutive checkpoints is removed. Given the checkpointing time, down-time, and recovery time, we derive the reliability of the checkpointing model. When the time-to-error follows an exponential distribution, we obtain the optimal checkpointing interval to achieve the maximum reliability.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.18 no.2
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• pp.125-140
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• 2007

Cultural contents should provide all the people web services to ensure accessibility without any obstacles as a core resource of nation including a code linking people and people beyond time and space. This study achieved that automated measure including 11 checkpoints and manual analysis including 11 criteria and 26 checkpoints of three areas in selected five web sites such as Culture Portal. Art Road, Korean Patterns, MFM, and e-Museum supported by Ministry of Culture & Tourism. As a result, web accessibility level of cultural contents analyzed it staying at the beginning level. This study Provided the directions in order to improve accessibility of cultural contents through showing real cases to practice for improving web accessibility.

• BMB Reports
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• v.36 no.1
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• pp.144-148
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• 2003

During the past 2 decades, radiation tumorigenesis researchers have focused on cellular and molecular mechanisms. We reviewed some of these research fields, since they may specifically relate to the induction of cancer by ionizing radiation. First, radiation-mediated mutation was discussed. Then the initiating event in radiation carcinogenesis, as well as other genetic events that may by involved, is discussed in terms of the possible role of the activation of genes and the loss of cell-cycle checkpoints.